The projects in progress involve the regulation of the synthesis and activity of RNA polymerase and ribosomes in the bacterium Escherichia coli. Composite plasmid or transducing phage DNAs carrying genes from the bacterial chromosome that specify RNA polymerase subunits or ribosome components are used as probes to monitor transcription of these genes. Synthesis of specific proteins is monitored by double isotope labeling and separation of cellular proteins by two-dimensional electrophoresis. Control of RNA polymerase gene expression and general transcription of the chromosome is being investigated under conditions where initiation of RNA chains is partially restricted using either a temperature sensitive rpoC mutant at semi-permissive temperatures or low concentrations of rifampicin. Such a restriction causes a specific 4-6 fold enhancement of rpoBC transcription and a parallel increase in the synthesis of beta and beta prime protein. Ribosome synthesis is transiently stimulated by 50% and beta galactosidase transcription is abolished. Amplification of genes coding for the beta and beta prime subunits of RNA polymerase also leads to elevated synthesis of RNA polymerase subunits.